Vapor generators



Oct. 30, 1962 R. H. EVANS VAPOR GENERATORS 2 Sheets-Sheet 1 Filed July 27, 1960 E/ D Jiy /9 7 25 INVENTOR.

Rlchard Henry Evans ATTORNEY Oct. 30, 1962 R. H. EVANS 3,060,904

VAPOR GENERATORS Filed July 27, 1960 2 Sheets-Sheet 2 2? INVENTOR.

Richard Henry Evans ilnited 'tates Eatent This invention relates to vapor generators having wall tubes arranged to operate with forced flow of the working medium therethrough. Such tubes are found, for example, in the superheater tubes of a natural circulation boiler provided with a superheater including tubes lining a furnace chamber wall area or in a forced flow, oncethrough'boiler with tubes lining furnace chamber walls.

More particularly, the invention is related to a forced flow tubulous boiler having circuits connected in parallel for flow of working medium and an upright furnace chamber space with walls lined by tube lengths of the circuits, wherein the tubulous lining has sections extending over respective zones one above the other and each formed by horizontal or substantially horizontal tube lengths of the respective circuits, the tube lengths of the circuits being distributed in the zones in a manner adapted to give-approximately equal heat inputs to the circuits.

In a vapor generator with horizontal or substantially horizontal furnace chamber wall tubes it is important that the tubes should be drainable and the mode of tube displacement of contiguous tubes at necessary fluid heater cleaner or the like apertures in a wall normally employed with vertical wall tubes cannot be used since there result, in tubes displaced in such manner, slugs of liquid which cannot be drained.

The present invention comprises a vapor generator with drainable parallel tube circuits arranged for force flow of the working medium therethrough and providing horizontal or substantially horizontal tube lengths lining a furnace chamber or/ and gas pass wall area and so arranged that sets of tube lengths extend in opposite directions at the wall from a location at which an aperture passes through the wall.

In one application of the invention each tube circuit includes tube lentghs disposed at different heights in the wall, the circuits are so arranged that pairs of sets of tube lengths extend in opposite directions from different locations in the wall and at least at one of the said locations an aperture passes through the wall.

When apertures through the wall are required for the passage of lances or sootblowers the required number of apertures will be provided at locations chosen as suitable for the lances or sootblowers.

The invention Will now be described, by way of example, with reference to the accompanying partly diagrammatic drawings, in which:

FIGURE 1 is an outside elevation of part of the wall of a furnace chamber at a location where sets of horizontal wall tubes enter and leave the wall by way of respective groups of upright transfer tubes and an access passageway for a sootblower is provided, the wall casing being omitted;

FIGURE 2 is a setcion on the line 2-2 of FIGURE I, viewed in the direction of the arrows, parts of the wall casing and insulation being shown;

FIGURE 3 is an outside elevation similar to that of FIGURE 1 showing two vertically spaced locations at which access passageways for sootblowers are provided, tubes entering the wall at the lower location and leaving the wall at the upper location; and

FIGURE 4 is a section on the line 44 of FIGURE 3 viewed in the direction of the arrows, parts of the casing and insulation being shown.

Mihfidd Patented Oct. 30, 1962 The invention has particular application to a forced flow tubulous boiler having circuits connected in parallel for the flow of Working medium and an upright furnace chamber space with walls lined by tube lengths of the circuits, wherein the tubulous lining has sections extending over respective zones one above the other and each formed by horizontal or substantially horizontal tube lengths of the respective circuits arranged in groups providing sets of adjacent tube length ends distributed around a furnace chamber space, the sets of tube length ends each include inlet ends and outlet ends and upright transfer' or connector tubes leading to the inlet ends of each of the said sets are connected with superjacent transfer or connector tubes leading from the outlet ends of the set, the said transfer or connector tubes constituting part of suspension means for the sections.

In one application of the present invention, as shown in FIGURES l and 2, a group I of six upright transfer or connector tubes 1A, 1B, 1C, 1D, 1E and IF, extends upwardly to one set 2 of six tube lengths 2A, 2B, 2C, 21), 2E and 2F at a location and another group 3 of six transfer or connector tubes 3A, 3B, 3C, 31), 3E and SF extends upwardly from the other set 4 of six tube lengths 4A, 4B, 4C, 4D, 4E and 4F at the location. The sets 2 and 4 of tube lengths extend horizontally in opposite directions from opposite sides of an aperture 5 which is embraced by connecting means 6 mechanically connect ing the respective groups 1 and 3 of transfer or connector tubes which extend upwardly to and upwardly from the said sets 2 and 4 of tube lengths. The connecting means 6 together with the groups 1 and 3 of transfer or connector tubes form parts of wall suspension means.

The connecting means are of elongated diamond shape in elevation, the diamond shaped elevation having its longitudinal axis vertical and being secured at its acute angled ends 6A and 6B by respective tie members 7 and 8 in the form of upright plates to cranked portions 9 and 10 of the groups 1 and 3 of transfer or connector tubes. The connecting means 6 are centrally apertured between front and rear faces so that the access passageway 5 extends normally or substantially normally to the sets 2 and 4 of tubes.

The tube lengths of the two sets 2 and 4 are so shaped at their adjacent extremities as substantially to screen the connecting means 6 from the furnace. Thus, above and below the aperture 5, corresponding tube lengths of the two sets 2 and 4, such as the tube lengths 2A and 4A below the aperture, are at their extremities contiguous,

as is seen in FIGURE 2, while, at the sides of the aperture 5, the extremities of corresponding tube lengths, such as tube lengths 2, 2C, 4, 4C, as seen in FIGURE 2, are appropriately spaced to help in defining an aperture 11 at the wall axially aligned with the passage 5 through the member 6. Each tube length is connected to a corresponding transfer or connector tube by a curved part projecting away from the furnace chamber to a location at a side of the connecting means 6 and downwardly or upwardly to the part of the transfer or connector tube welded to the connecting means 6. Thus the tube length 26 is connected to tranefer tube 10 by a curved part projecting away from the furnace chamber side of the sets 2 and 4 of wall tubes, to a location at the side of the connecting means 6 and then downwardly to connect by way of a cranked portion with the transfer tube 1C. The curved parts, such as the curved part 12C of tube 2C, extend away from the furnace chamber horizontally or at such an inclination as to ensure drainability of the tubes.

As shown, on opposite sides of the connecting means 6, the'connections between the sets 2 and 4 of horizontal wall tubes and the groups 1 and 3 of upright tube parts include upright tube parts such as 1D, 1E, 1F, 3Df,

3E, and 3F which extend parallel or substantially parallel to the upright axis of the diamond shaped connecting means 6. It will be appreciated that these portions on opposite sides of the connecting means could be bent to follow the sloping sides of the connecting means to provide better cooling thereof, while maintaining the free drainability of the tubes.

Referring to FIGURE 2, the transfer tube parts surrounding the connecting means 6 are enclosed by an extension 13 of the skin casing 14 of the Wall tubes. The extension 1 3 is connected at its inner edges to the casing 14 by suitable flexible sealing strips 15, and has upright sides 16 and upper and lower parts, corresponding to the contours of the cranked portions 9 and 10 of the groups of transfer tubes as indicated in FIGURE 1 by broken lines 17.

At the outer end of the connecting means 6, the extension 13 is provided with a fiat closure plate 18, secured to the extension and to the connecting means 6, the plate 18 .being centrally apertured at 19 to expose the access passageway 5. Suitable removable closure means, in the form of a cover plate 25 suitably secured, as by bolts, to the member 6, are provided for closing the passageway on withdrawal of a sootblower tube. The extension 13 and the casing 14 are provided externally with a layer of heat insulating matetrial 20 in normal manner.

The invention has particular application to a boiler wherein the furnace chamber includes a firing zone at which at least one furnace chamber wall is provided with burner ports in the neighborhood of which the wall is lined with a group of upright tubes and pair of horizontal or substantially horizontal tube lengths lining the walls between the sides of the group or groups of upright tubes are so arranged that the tube lengths of each pair extend 'in opposite directions from each of the adjacent pairs of ends which are substantially equidistantly spaced from opposite sides of the group of upright tubes or from adjacent sides of different. groups of upright tubes and each tube length of the pair extends to and from one of the said sides. Clearly such a construction may be modified by substituting for each pair of horizontal or substantially horizontal tube lengths a pair of sets of horizontal or substantially horizontal tube lengths. Moreover, a similar construction may be adopted, for example, at an upper region of a furnace chamber from which extends a lateral gas pass, the adjacent pairs of sets of ends then being substantially equidistantly spaced from the gas outlet from the furnace chamber or from the gas outlet from the lateral pass.

In another application of the present invention shown in FIGURES 3 and 4, groups 31 and 32 of six transfer or connector tubes extend upwardly to respective sets of tube lengths of two sets 33 and 34 of six tube lengths at one location, groups 35 and 36 of six transfer or connector tubes extend upwardly from respective sets of tube lengths of two sets 37 and 38 of six tube lengths at a second location immediately above but spaced from the first location and connecting means 39 embrace respective apertures 43 and 44 at the locations. The connecting means 39 extend past tube lengths 40 of other sets of tube lengths intermediate the two locations and mechanically connect the respective groups 31 and 32, and 35 and 36 of transfer or connector tubes which extend upwardly to the sets 33 and 34 of tube lengths at the first location and upwardly from the tube sets 37 and 38 at the second location and the connecting means 39 and the groups 31, 32, '35 and 36 of transfer tubes together form part of wall suspension means.

The connecting means 39 comprise two spaced parallel tension members 41 and 42 in the form of plates extending normally to the wall and vertically between cranked parts 31A, 32A, 35A and 36A of respective groups 31, 32, 35 and 36 of transfer or connector tubes to which the members are welded, one member 41 being welded to the cranked parts 31A and 35A of the transfer or connector tubes of the groups 31 and 35 associated with corresponding sets. 33 and 37 of tube lengths at the two locations, and the other member 42 being welded to the cranked parts 32A and 36A of the transfer or connector tubes of the groups 32 and 36 associated with the other corresponding sets 34 and 38 of tube lengths at the two locations.

At the apertures 43 and 44, the tube lengths of adjacent sets and the associated transfer or connector tubes are formed in a similar manner to that described above in connection with the embodiment of FIGURES 1 and 2. Thus the tube lengths of the sets 33 and 34, and of the sets 37 and 38 are so shaped at their adjacent extremities as substantially to screen the parts of the connecting means 39 adjacent the apertures 43 and 44 from the furnace. Above and below each of the apertures 43 and 44, corresponding outermost tube lengths of the sets are contiguous at their extremities, while at the sides of the apertures extremities of corresponding tubes are appropriately spaced to help in defining the associated aperture. Each tube of the sets 33, 34, 37 and 38 is connected to a corresponding transfer tube of the associated group by a curved part projecting away from the furnace chamber to a location at a side of the tension member 41 or 42 remote from the apertures. The curved parts of the tube lengths extend away from the furnace horizontally or at such an inclination as to ensure drainability of the tube lengths.

At the apertures 43 and 44, respective aperture defining plates 45 and 46 are provided, welded at their peripheries to the tube extremities bounding the associated apentures. The plates 45 and 46 are centrally apertured and at the apertures inner ends of respective access tubes 47 and 48 are connected to the plates, the tubes 47 and 48 extending outwardly normal to the wall and between the tension members 41 and 42 of the connecting means 39. The tubes 47 and 48 terminate at their outer ends adjacent outer edges of the tie members 41 and 4-2, to which the tubes are Welded and are suitably welded to an outer casing part 49, as seen in FIGURE 4, which serves to provide a closure to the skin casing 50 of the furnace Wall. The casing part 49 comprises an upright vertically elongated U section casing member having side parts 51 embracing the parts of the transfer tubes on opposite sides of the connecting means 39. Inner edges of the side parts 51 are suitably connected with the skin casing 50 by upright V section flexible sealing strips allowing relative horizontal movement between the side parts 51 and the skin casing 50. Above and below the connecting means 39, the casing part 49 is suitably connected to respective vertical casing parts serving to encase the up right transfer tube groups 35 and 36, and 31 and 32. At the outer ends of the access tubes 47 and 48, the casing part 49 is suitably apertured for access to the tubes which provide access means for sootblower tubes. Removable closure means, in the form of cover plates 26, are suitably provided and secured at the outer ends of the access tubes'47 and 48, for closing the apertures on removal of the associated sootblowers.

It will be appreciated that an access aperture need not be provided at both locations of an arrangement such as is described in connection with FIGURES 3 and 4, but may only be provided at one of the locations. It will be understood that, in such circumstances, the tube lengths at the location where no aperture is provided will be contiguous at their extremities.

It will be appreciated that when the transfer or connector tubes serve as part of the suspension means of a wall, the upright transfer or connector tubes are arranged in vertically extending sets distributed around the furnace chamber. It therefore follows that the locations chosen for the apertures may be selected from locations distributed at frequent intervals both across the Wall and in the height of the wall. It will be further understood from the above description that the apertures are provided without interfering with the drainability of the wall tubes.

My invention may also be applied to a tubulous natural circulation boiler having an upright furnace chamber the walls in the lower region of which are lined with upright vapor generating tubes and the walls in an upper region of which are lined with vapor heating tubes connected in a number of parallel circuits each of which includes horizontal or substantially horizontal tube lengths arranged in zones one above the other in a manner adapted to result in approximately equal heat inputs to the circuits, the said tube lengths being supported by upright tubes connected in circuit with the upright vapor generating tubes. It will be appreciated that the present invention may be applied in the said upper region in the provision of apertures through the furnace chamber walls.

While in accordance with the provisions of the statutes I have illustrated and described herein the best form and mode of operation of the invention now known to me, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by our claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

What is claimed is:

1. In combination with a wall including a vertical row of contiguous horizontally extending drainable fluid cooled tube lengths arranged for parallel flow of fluid therethrough and providing a boundary for a chamber confining high temperature gases, means forming an opening in said wall and comprising two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said opening, each of the tube lengths of both of said sets having one end disposed contiguous to said opening, a frame having an interior passage adapted to register with said opening, a first group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about one side of said frame and directly connected to said one ends of one of said sets of tube lengths to provide continuity between each connector tube and its corresponding tube length, a second group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about the opposite side of said frame and directly connected to said one ends of the other set of tube lengths to provide continuity between each connector tube of said second group and its corresponding tube length, and closure means for said opening associated with said frame.

2. In combination with a wall including a vertical row of contiguous horizontally extending drainable fluid cooled tube lengths arranged for parallel flow of fluid therethrough and providing a boundary for a chamber confining high temperature gases, means forming an opening in said wall and comprising two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said opening, each of the tube lengths of both of said sets having one end disposed contiguous to said opening, a frame having an interior passage adapted to register with said opening, a first group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about one side of said frame and directly connected to said one ends of one of said sets of tube lengths to provide continuity between each connector tube and its corresponding tube length, a second group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about the opposite side of said frame and directly connected to said one ends of the other set of tube lengths to provide continuity between each connector tube of said second group and its corresponding tube length, means for supporting said sets of tube lengths including means mechanically connecting said first and second groups of connector tubes, and closure means for said opening associated with said frame.

3. In combination with a wall including a vertical row of contiguous horizontally extending drainable fluid cooled tube lengths arranged for parallel flow of fluid therethrough and providing a boundary for a chamber confining high temperature gases, means forming an opening in said wall and comprising two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said opening, each of the tube lengths of both of said sets having one end disposed contiguous to said opening, a frame having an interior passage adapted to register with said opening, a first group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about one side of said frame and directly connected to said one ends of one of said sets of tube lengths to provide continuity between each connector tube and its corresponding tube length, a second group of upwardly extending fluid cooled connector tubes disposed in most part exteriorly of said wall and about the opposite side of said frame and directly connected to said one ends of the other set of tube lengths to provide continuity between each connector tube of said second group and its corresponding tube length, means for supporting said sets of tube lengths including means mechanically connect-ing said frame to said first and second groups of connector tubes, and closure means for said opening associated with said frame.

4. In combination with a wall including a vertical row of contiguous horizontally extending drainable fluid cooled tube lengths arranged for parallel flow of fluid therethrough and providing a boundary for a chamber confining high temperature gases, means forming an opening in said wall comprising two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said opening, the tube lengths of one of said sets having their inlet ends disposed contiguous to said opening, the tube lengths of the other of said sets having their outlet ends disposed contiguous to said opening, a frame having an interior passage adapted to register with said opening, a first group of fluid cooled connector tubes disposed in most part exteriorly of said wall and about one side of said frame and extending upwardly to and directly connected to the inlet ends of said one set of tube lengths to provide continuity between each connector tube and its corresponding tube length, a second group of fluid cooled connector tubes disposed in most part exteriorly of said wall and about the opposite side of said frame and extending upwardly from and directly connected to said outlet ends of said other set of tube lengths to provide continuity between each connector tube of said second group and its corresponding tube length, and closure means for said opening associated with said frame.

5. In combination with a wall including a vertical row of contiguous horizontally extending drainable fluid cooled tube lengths arranged for parallel flow of fluid therethrough and providing a boundary for a chamber confining high temperature gases, means forming a first opening in said wall and comprising two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said opening means forming a second opening in said wall at a higher elevation than said first opening and comprising another two sets of said tube lengths extending in opposite directions and disposed on opposite sides of said second opening, the tube lengths of said first named sets having their inlet ends disposed contiguous to said first opening, the tube lengths of said second named sets having their outlet ends disposed contiguous to said second opening, a first frame having an interior passage adapted to register with said first opening, a second frame having an interior passage adapted to register with said second opening, a first group of fluid cooled connector tubes disposed in most part exteriorly of said wall and on opposite sides of said first frame and extending upwardly to and directly connected to said inlet ends of said first named sets of tube lengths to provide continuity between each connector tube and its corresponding tube length, a second group of fluid cooled References Qited in the fiie of this patent connector tubes disposed in most part exteriorly of said m all and on opposite sides of said second frame and UNITED STATES PATENLS extending upwardly from and directly connected to said 2,125,557 Jackson Aug 9, 1938 outlet ends of said second named sets of tube lengths 5 to provide continuity between each connector tube of said 2357302 Kerr et Sept second group and its corresponding tube length, and cio- 2,896,591 Schmedter y 23, 1939 sure means for each of said openings associated with the corresponding frame. 

